Premium
Salicylic acid binding of mitochondrial alpha‐ketoglutarate dehydrogenase E2 affects mitochondrial oxidative phosphorylation and electron transport chain components and plays a role in basal defense against tobacco mosaic virus in tomato
Author(s) -
Liao Yangwenke,
Tian Miaoying,
Zhang Huan,
Li Xin,
Wang Yu,
Xia Xiaojian,
Zhou Jie,
Zhou Yanhong,
Yu Jingquan,
Shi Kai,
Klessig Daniel F.
Publication year - 2015
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/nph.13137
Subject(s) - tobacco mosaic virus , biology , nicotiana benthamiana , biochemistry , plant defense against herbivory , citric acid cycle , alternative oxidase , mitochondrion , gene silencing , oxidative phosphorylation , microbiology and biotechnology , enzyme , virus , virology , gene
Summary Salicylic acid ( SA ) plays a critical role in plant defense against pathogen invasion. SA ‐induced viral defense in plants is distinct from the pathways mediating bacterial and fungal defense and involves a specific pathway mediated by mitochondria; however, the underlying mechanisms remain largely unknown. The SA‐binding activity of the recombinant tomato ( Solanum lycopersicum ) alpha‐ketoglutarate dehydrogenase ( Sl α‐k GDH ) E2 subunit of the tricarboxylic acid (TCA) cycle was characterized. The biological role of this binding in plant defenses against tobacco mosaic virus (TMV) was further investigated via Sl α ‐k GDH E2 silencing and transient overexpression in plants. Sl α‐ kGDH E2 was found to bind SA in two independent assays. SA treatment, as well as Sl α ‐k GDH E2 silencing, increased resistance to TMV. SA did not further enhance TMV defense in Sl α ‐k GDH E2 ‐silenced tomato plants but did reduce TMV susceptibility in Nicotiana benthamiana plants transiently overexpressing Sl α ‐k GDH E2 . Furthermore, Sl α ‐k GDH E2 ‐silencing‐induced TMV resistance was fully blocked by bongkrekic acid application and alternative oxidase 1a silencing. These results indicated that binding by Sl α‐k GDH E2 of SA acts upstream of and affects the mitochondrial electron transport chain, which plays an important role in basal defense against TMV. The findings of this study help to elucidate the mechanisms of SA‐induced viral defense.